The present invention is directed to compositions related to proteins which function in controlling development and differentiation of mammalian cells, e.g., cells of a mammalian immune system. In particular, it provides proteins and mimetics, and antibodies which regulate development, differentiation, and function of various cell types, including hematopoietic cells.
The circulating component of the mammalian circulatory system comprises various cell types, including red and white blood cells of the myeloid, lymphoid, megakaryotoid, or the erythroid cell lineages. See, e.g., Rapaport (1987) Introduction to Hematology (2d ed.) Lippincott, Philadelphia, Pa.; Jandl (1987) Blood: Textbook of Hematology, Little, Brown and Co., Boston, Mass.; and Paul (ed. 1993) Fundamental Immunology 3d ed., Raven Press, N.Y. Progression through various stages of differentiation are regulated by various signals provided to the cells, often mediated through a class of soluble proteins known as the cytokines. Within this class of molecules is a group known as the chemoattractant cytokines, or chemokines. See, e.g., Schall (1994) xe2x80x9cThe Chemokinesxe2x80x9d in The Cytokine Handbook (2d ed.) Academic Press; Schall and Bacon (1994) Current Opinion in Immunology 6:865-873.
Although the chemokines have not been tested over the full spectrum of biological activities, the best described biological functions of these molecules relate to chemoattraction of leukocytes. However, new chemokine-like molecules are being discovered, and their biological effects on the various cells responsible for immunological responses are topics of continued study.
Many observations indicate that other factors exist whose functions in hematopoiesis, immune development, and leukocyte trafficking are heretofore unrecognized. These factors provide possible biological activities whose spectra of effects are distinct from known differentiation, activation, or other signaling factors. Moreover, new biological activities of chemokine-like molecules on other cell types have yet to be discovered. The absence of knowledge about the structural, biological, and physiological properties of the regulatory factors which regulate, e.g., hematopoietic cell physiology in vivo, prevents the modification of the effects of such factors. Thus, medical conditions where regulation of the development or physiology of relevant cells is required remain unmanageable.
The present invention is based, in part, upon the discovery of new genes, designated dendrokines, encoding members of the class of CC chemokines. These dendrokines appear to be specifically expressed in dendritic cells. It embraces agonists and antagonists of the dendrokines, e.g., mutations (muteins) of the natural sequences, fusion proteins, chemical mimetics, antibodies, and other structural or functional analogs. It is also directed to isolated genes encoding proteins of the invention. Various uses of these different protein or nucleic acid compositions are also provided.
The present invention provides a substantially pure dendrokine; a fusion protein comprising dendrokine sequence; an antibody or antigen binding fragment thereof which exhibits specificity of binding to a dendrokine; and a nucleic acid encoding a dendrokine or fusion protein thereof.
In dendrokine embodiments, the chemokine may comprise a mature dendrokine sequence of Table 1; have a natural sequence; exhibit a post-translational modification pattern distinct from natural dendrokine; be 3-fold or fewer substituted from a natural sequence; be detectably labeled; be attached to a solid substrate; or be denatured. The invention also embraces a sterile composition comprising the dendrokine. The dendrokine composition may also attract a cell of hematopoietic origin.
In fusion protein embodiments, the protein may comprise either sequence of Table 1; and/or sequence of another cytokine or chemokine.
In antibody embodiments, the dendrokine can be a human protein or denatured; or the antibody may be raised against a peptide sequence of Table 1 or a purified primate dendrokine; may be a monoclonal antibody; be from a rabbit or mouse; be detectably labeled; be attached to a solid substrate; or bind to said dendrokine with a Kd of at least about 300 xcexcM. Binding fragments of the antibodies can be an Fv fragment, an Fab fragment, or an F(ab)2 fragment; be fused to another protein segment; or be coupled to another chemical moiety.
The invention further provides methods of making a dendrokine-antibody complex by contacting a primate dendrokine to a binding antibody; and may further allow purification of the dendrokine or antibody.
In nucleic acid embodiments, the chemokine may be from a primate, including a human, or have a naturally occurring sequence. The nucleic acid may have a natural sequence; hybridize at 65xc2x0 C. and 50 mM salt to the coding sequence of Table 1; comprise a coding sequence of Table 1; be detectably labeled; be an expression vector; be operably associated with a regulatory or control sequence; be at least about 330 nucleotides in length; be a PCR product, or comprise a deoxyribonucleic acid nucleotide. The invention also provides a method of making a chemokine protein comprising a step of expressing such a nucleic acid.
The invention also provides a kit comprising: a substantially pure dendrokine, or fragment thereof; an antibody which binds with specificity to a mammalian dendrokine; or a nucleic acid encoding a dendrokine or peptide of about 17 amino acids. The kit may also be capable of making a qualitative or quantitative analysis.
In another embodiment, the invention provides methods of modulating physiology or development of a cell comprising contacting the cell with an agonist or antagonist of a mammalian dendrokine. The antagonist may be an antibody against a mammalian dendrokine and result in the regulation of autoimmunity, tissue rejection, or an undesired response to an antigen. In embodiments encompassing an agonist, the modulating can result in the regulation of an infectious disease, a vaccine response, or a cancer.